1. Field of the Invention
The present invention relates to an image recording apparatus of such a type that a transfer material is supported on transfer material supporting means and transferably receives a toner image from an image bearing member, and more particularly to the cleaning of the transfer material supporting means and the operation of corona dischargers relating to the cleaning step.
2. Description of the Prior Art
In the conventional image transfer type electrophotographic image forming systems such as copying machines, a transfer material is supported on a drum or belt-shaped transfer material supporting member. The transfer material and the supporting member are synchronously moved close to or in contact with an image bearing member such as a photosensitive drum or the like. As the transfer material supporting member is used for an increased time period, it is more contaminated by the toner particles conveyed on the image bearing member. Thus, the transfer material may be contaminated at its back face or the performance of the transfer may be degraded. In order to overcome these problems, it is customary to provide a cleaning member for cleaning the transfer material supporting means before and after the copying operation. The cleaning member is often in the form of a brush as disclosed in U.S. Pat. No. 3,819,263. In general, the toner particles may be somewhat scattered around during the above cleaning step. The amount of scattered toner particles is larger particularly when a brush is used as cleaning means. On the other hand, there are corona dischargers used in transferring and charge-removing which are located near the transfer material supporting member. Thus, the above cleaning step must be carried out near these corona dischargers. As a result, the scattered toner particles may electrostatically be attracted to the discharging wires and shield plates of the corona dischargers under the influence of the charge produced by the corona dischargers or the potential generated by the applied voltage. This results in the creation of spark discharging. In the prior art, there have been proposed various approaches for preventing the scattered toner particles from depositing on the corona dischargers. One of these approaches is the use of a fan system for introducing air around the cleaning member. There was however no satisfactory approach in the prior art. It has been practical that the dischargers were manually cleaned by an operator.